ROBBER FLIES OF THE WORLD 



481 



Wings : The anterior branch of the third vein arises 

 from an oblique crossvein with a minute, basal spur or 

 may arise gi-adually. The second submarginal cell is 

 narrow throughout. The anterior branch of the third 

 vem ends shortly before the wing apex and the posterior 

 branch ends shortly behind. The fourth posterior cell 

 is closed and stalked; fork of the third vein distinctly 

 beyond the posterior crossvein. Anal cell closed and 

 stalked. Alula large, ambient vein complete. 



Abdomen: The abdomen is similar to that of 

 Eicherax but with slender bristles along the subpos- 

 terior margin laterally on all tergites. Only those of 

 the fii'st tergite are stout. Fii-st two sternites with 

 scattered, long pile ; fii-st sternite bare with no pile and 

 poUinose only, differing from Eicherax. Males with 

 eight tergites, both the seventh and eighth greatly 

 shortened, especially in the middle, their sternites, how- 

 ever, long. Since the terminalia tend to be flexed up- 

 ward, the last tergite may be also bent upward. The 

 male terminalia, especially the superior forceps, wliich 

 are not divided to the base, are greatly expanded 

 laterally and widened; they are also convex laterally. 

 Gonopod short, convex and bulbous, but wedged in be- 

 tween the laterally expanded and convex hypandrium. 

 Females with the ovipositor composed of the moderate- 

 ly elongate, laterally compressed eighth segment, wliich 

 is only a little longer than the seventh. Ninth segment 

 and the proctiger short. 



Distribution: Neotropical: Lecania annulipes Mac- 

 quart (1846) ; apicalis Bromley (1934) ; complicata 

 James (1953) ; copulatus Wiedemann (1819) ; ctesicles 

 Walker (1851) ; genitalis Bromley (1934) ; hilari Mac- 

 quart (1838) ; Testes Williston (1901) ; Isucopygus Wie- 

 demann (1828) ; rufpes Macquart (1838) ; virilis Wie- 

 demann (1828). 



Oriental: Lecania tahescens Eondani (1875). 



Comitry unknown. Lecania dasius Walker (1849) ; 

 femoratus Macquart (1838). 



Subgenus Pachychaeta Bigot 

 FiGUKES 699, 2440, 2446 



Pachychaeta Bigot, Ann. Soc. Ent. France, ser. 3, vol. 5, p. 545, 

 1857. Type of subgenus : Erax annulipes Macquart, 1846, 

 by original designation. 



Lecania Macquai-t was foimded on a species with the 

 apex of the arista flattened and lamellate to a remark- 

 able extent in both sexes, although a little more exten- 

 sive in males. Pachychaeta, on the other hand, was 

 founded on flies which, because of similar face, wing 

 venation and tenninalia, obviously are related to Le- 

 cania, yet have the aristal apex much less conspicuously 

 flattened and in many sjDecies the flies can hardly be de- 

 termined on the character of the arista. For this rea- 

 son I believe it is necessary to retain Pachychaeta in a 

 subgeneric sense. 



Genus Catostola Hull 



FiouBES 349, 394, 786, 1512, 1521, 1545, 1554, 2201, 2205. 2484, 



2501 



Catostola Hull, Brasileira Biol., vol. 18, no. 3, p. 320, 1958. Type 

 of genus : Catostola carrerai Hull, 1958, by original desig- 

 nation. 



Small flies, comparatively slender, with broad face 

 only slightly produced below. Short, third antennal 

 segment has a long, fine style and the hind femur is 

 distinguished by a patch of dense, short, stout, sub- 

 tuberculate bristles situated medially on the apical 

 third. Also, the male terminalia are curious on accoimt 

 of the short forceps and the greatly exaggerated eighth 

 sternite, which is wide at the base and extends at least 

 as far as the forceps. Length 15 mm. 



Head, lateral aspect : The head is of medium length. 

 The face on the upper half is nearly plane with the eye ; 

 it is a little produced unmediately below the antenna 

 and the lower half of the face is slightly produced and 

 rounded and more conspicuous on account of the re- 

 cession of the eye. The occiput everywhere bears short, 

 dense, fine pile below ; along the middle it has slender 

 bristles, which are distinctly turned downward, and 

 above at the upper eye corner 3 or 4 stout, proclinate 

 bristles. Proboscis rather slender, tapered to a blimt 

 point near the apex and with a subapical crease. Pal- 

 pus moderately stout and cylindrical with numerous, 

 stout bristles. The antenna is attached a little above 

 the middle of the head; the first segment is compara- 

 tively elongate and slender, more than twic« as long 

 as the short, bead-like second segment and also longer 

 than the long, oval tliird segment. The first segment 

 bears setae at the dorsal apex and ventrally as well as 

 a number of comparatively stout though short, oblique 

 bristles. Second segment rather densely setate above 

 and below. The third segment is narrowed apically 

 and bears a scarcely noticeable, very short microseg- 

 ment and a rather long, slender style which is a little 

 thicker distally and has bristles at apex. This style is 

 a little longer than all 3 segments together. 



Head, anterior aspect: The width of the head is 1% 

 the height and the head is a little wider below than 

 above. The enlarged anterior facets are demarcated 

 and this portion of the eye is rather flattened. The face 

 is rather wide beneath the antemia, not quite a fifth of 

 the head width and it is distinctly wider below. The 

 whole surface is finely appressed micropubescent. 

 There are a few hairs on the upper half along the eye 

 margin, short and appressed. In the middle the lower 

 half bears a large, dense, triangular patch of numerous, 

 long, slender bristles mostly wliite but partly black. 

 The medial elements are stouter and there is a rather 

 dense fringe along tlie subepistomal margin. Cheeks 

 short. Front very slightly widened anteriorly, nar- 

 rowed behind and the vertex distinctly narrowed, mod- 

 erately excavated with sloping sides. The small ocel- 

 larium bears a pair of moderately long, postocellar 

 bristles curved forward. 



